LARGO — As an interviewer for the Pinellas-Pasco Public Defender's Office, Alexandra Petitt had access to inmates in the county jail. Petitt talked to them to gather information for their attorneys to use at hearings.

In November, Petitt began visiting a man named Tywan Armstrong, an inmate who had been in jail for several months on charges that included cocaine trafficking. The pair met multiple times for what Petitt said was official business for the Public Defender's Office. They met in private rooms reserved for attorneys and their clients. By law, deputies aren't allowed to monitor the rooms.

Several weeks later, Pinellas sheriff's officials said, deputies found out what was really going on behind closed doors.

Armstrong, 30, was in fact Petitt's boyfriend. And the 20-year-old was using her official position to have sex with him and to smuggle him marijuana, officials say.

Wednesday, authorities arrested Petitt on two charges of official misconduct.

An anonymous tip led sheriff's officials to launch an investigation into Petitt on Dec. 14.

Detectives verified the visits through jail records. On the records, which Petitt signed, she indicated she was there on behalf of the Public Defender's Office, where she had worked since August.

Investigators listened to recorded phone calls between the two, which substantiated the claims about the drugs and sex, officials said. The conversations also included information about Petitt possibly becoming pregnant as a result of the visits.

Detectives also hit on another important fact to build their case: Armstrong, it turned out, was being represented by a private lawyer, not a public defender.

"There would be no reason for her to be interviewing him on their behalf," the Sheriff's Office said in a news release.

Pinellas-Pasco Public Defender Bob Dillinger said this was the first time anything like this had happened in the Public Defender's Office.

Reached on Wednesday evening, Dillinger referred to Petitt as a former employee. He said she had been a part-time hourly worker who was an a intern from the University of South Florida.

Her job was to interview recently arrested defendants, to provide information for attorneys to use in bond reduction hearings.

Petitt does not have any previous arrests in Florida, records show.

It is unclear how long she and Armstrong, who has arrests dating back to 1995, had been in a relationship.

Armstrong had been an inmate in the Pinellas jail since January 2009, when he was arrested on various charges including cocaine possession and trafficking, operating a drug house, failing to appear in court, fleeing and eluding, habitually driving with a suspended or revoked license, battery on a law enforcement officer and obstruction.

Tuesday, he was transferred to the custody of the Florida Department of Corrections. Court records indicate he was sentenced to 18 months in prison.

Detectives are continuing their investigation into Petitt's actions and could add additional charges, the sheriff's office said.

She was being held at the Pinellas County jail Wednesday night in lieu of $10,000 bail.

Kameel Stanley can be reached at kstanley@sptimes.com or (727) 893-8643.